Dangling Pointer Vulnerability in Linux Kernel's ksmbd Package
Summary
CVE-2025-37778: In the Linux kernel, the following vulnerability has been resolved: ksmbd: Fix dangling pointer in krb_authenticate krb_authenticate frees sess->user and does not set the pointer to NULL. Affects linux versions < 6.1.135-1. Fixed in 6.1.135-1. How to fix ↓
Check if this vulnerability affects your application
Upload a manifest or SBOM and we'll show whether you're affected, plus every other risky package in the same scan.
No signup required · Results in about 60 seconds
Background
The Linux kernel is a core component of many operating systems, providing essential services and managing hardware resources. The ksmbd module allows for SMB (Server Message Block) protocol support, enabling file sharing and network communication. This vulnerability affects the kernel's handling of user sessions, potentially leading to memory access issues.
Vulnerability Detail
In the Linux kernel, specifically within the ksmbd module, a vulnerability has been identified in the krb_authenticate function. This function frees the sess->user pointer without setting it to NULL, which can lead to a dangling pointer situation. If ksmbd_krb5_authenticate is called and fails to reinitialize sess->user, subsequent access to this pointer in smb2_sess_setup may result in accessing freed memory. This can lead to undefined behavior, crashes, or potential exploitation by an attacker.
How To Fix
Minimum fixed version
6.1.135-1
This is the first release that contains the fix.
sudo apt-get install --only-upgrade linuxTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
Currently, there are no specific workarounds provided for this vulnerability. It is advisable to monitor for updates and apply them as soon as they become available.
Conclusion
The CVE-2025-37778 vulnerability in the Linux kernel's ksmbd module poses significant risks due to potential memory access issues. Users are encouraged to update their systems to the patched version as soon as it becomes available to ensure security and stability.
See every vulnerability recorded for linux →
FAQ
CVE-2025-37778 is a vulnerability in the Linux kernel's ksmbd module that can lead to accessing freed memory due to a dangling pointer.
This vulnerability can lead to crashes or undefined behavior in applications that rely on the ksmbd module, potentially allowing attackers to exploit the issue.
Versions of Linux using the ksmbd module are affected, particularly Debian 11, 12, and 13. Check for updates to see if a patched version is available.
While there are no specific workarounds, it is crucial to monitor for updates and apply them as soon as possible to mitigate risks.
You can use Vulert, which monitors open-source vulnerabilities in real-time. Visit Vulert Scanner to check if your application is affected without needing to sign up.
Related vulnerabilities
Recent vulnerabilities recorded for linux.
